Screen Size Comparison Calculator

What does this tool compare?

Two screens, side by side — phone, tablet, laptop, monitor, or TV — from just their resolution and diagonal size. Pick a device preset or enter custom numbers for each screen to see resolution, physical dimensions, viewing area, PPI (pixels per inch), pixel pitch, pixel density category, and Retina status compared directly.

How this tool works

1. For Screen A and Screen B, either pick a Preset (common phones, tablets, laptops, monitors, and TVs) or enter a custom Width, Height, and Diagonal size (in inches or centimeters).
2. The Side-by-Side Details table shows ten metrics for both screens, with a ✓ marking whichever screen wins each comparable metric (larger area, higher PPI, more pixels, finer pixel pitch).
3. The Summary gives a plain-language readout of how many times larger, sharper, or higher-resolution one screen is versus the other.

The math behind it

• Physical size: the diagonal is split into width and height using the resolution's aspect ratio (atan2(height, width)), then cos/sin of that angle times the diagonal gives the physical width and height.
• PPI: the diagonal in pixels (√(width² + height²)) divided by the diagonal in inches.
• Pixel pitch: 25.4 / PPI, in millimeters — the physical spacing between pixel centers.
• Density category: PPI bucketed into the standard Android-style tiers (ldpi < 140, mdpi < 200, hdpi < 280, xhdpi < 400, xxhdpi < 560, else xxxhdpi).
• Retina: PPI at or above 220, Apple's usual "Retina" threshold.

Common uses

• Deciding whether a phone/tablet upgrade meaningfully improves sharpness or size
• Comparing two monitors before a desk setup purchase
• Checking whether a TV's PPI is "too low" for close-up viewing (e.g. as a monitor)
• Understanding why two screens with the same resolution can look very different in sharpness

Privacy

This tool runs entirely in your browser. Your input is never uploaded to a server.